Tag: conservation science

Just below the summit, we scrambled past enormous boulders to an unhappy sight—a small group of beautiful aspens in big trouble.

As curator of woody plants at the Chicago Botanic Garden, I’m interested in what’s happening to quaking aspen (Populus tremuloides) because the trees have become increasingly threatened by geologic disturbance and climate change. The Garden is part of a research group that’s working to collect root pieces and other genetic material from the aspens in the Chisos Mountains of west Texas; the material will allow us to raise the trees in cultivation and then plant new ones in the wild. The quaking aspens project is just one part of a broader Garden goal to protect species and promote biodiversity.

As part of the initiative, I met with Adam Black, director of horticulture at the famed Peckerwood Garden in Hempstead, Texas. Adam is a plant geek at heart and knows the Chisos Mountains intimately from 20-plus years of exploring there. He put together the collaboration between the Chicago Botanic Garden, Peckerwood Garden, the National Park Service, and the University of Florida School of Forest Resources and Conservation.

Quaking aspen growing out of the boulder field below Emory Peak, Big Bend National Park (white trunks visible in foreground)

In mid-February, Adam and I began the long, steep trek toward Emory Peak, in Big Bend National Park, gaining about 1,800 feet of elevation in 4 miles. Passing through Laguna Meadows, I first glimpsed the stunning white bark of the aspens growing out of enormous boulders above us. Adam and I dropped our packs and scrambled across the boulder field, photographing the terrain and aspens as went.

The chalk-white bark of these quaking aspens (Populus tremuloides) contrasts with the Mexican pinyon pines (Pinus cembroides) growing in the boulder field.

When we reached the trees, it quickly became clear that this grove of aspens was unlike any other I had seen before. Aspens usually grow in enormous clonal groves, which means that the trees are essentially a single plant, connected by one elaborate root system. The grove below Emory Peak includes only 40 trees or so, in poor health. Jason Smith, Ph.D., forest pathologist at the University of Florida in Gainesville, believes that the trees are under stress from the radiant heat of the rocks in which they are growing. When the trees grow to about 25 feet high, they get a canker disease—a fungal infection—and quickly die.

Adam and I collected root pieces and shoots from six separate trees in the grove, all good genetic material that will allow us to cultivate the plants. Reaching the roots was no easy task. The aspens are growing in the remains of what appears to be a major rock collapse from an igneous intrusion, or rock formed from intense heat that has crystalized into molten magna. While most aspen colonies spread upward from roots in less than 18 inches of soil, these trees grow through several feet of stacked boulders. As we moved from tree to tree, I struggled to keep my footing on the shaky boulders and tried not to cause a rock slide down the mountain.

With GPS data and root sections in hand, Adam and I climbed up to the mountain’s East Rim, where we were rewarded with stunning views of the Chisos Mountains, canyons carved out by the Rio Grande River and Maderas Del Carmen Reserve in northern Mexico. The next morning, camping on the mountain rim, watching the sunrise cascading across the United States-Mexico border, I forgot about the 8-mile descent ahead of me until it was time to pack up and go. During the hike down, Adam and I stopped by the second group of quaking aspens that we’re studying; a month earlier, Adam and Dr. Smith had collected root pieces from the trees for propagation.

Sunlight fading over Sierra Del Carmen in Coahuila, Mexico

After the team cultivates new plants from the genetic material we collected, the trees will be distributed to botanic gardens and arboreta across the country and added to the institutions’ conservation collections. The team is also doing genetic testing on the Chisos Mountains trees to determine how they relate to other aspen populations.

The number of women in science is pretty dismal. Despite earning about half the doctorates in science, only 21 percent of full science professors in the United States are women,* but I feel very fortunate to work at an institution committed to inclusiveness and diversity. At the Chicago Botanic Garden, 25 of our 47 scientific staff are women; our graduate student body is 61 percent female.

Still, implicit gender biases persist in science, resulting in fewer women in top positions, along with women earning less pay, winning fewer grants, and publishing fewer papers. This comes at a time when we are faced with numerous grand challenges in science and need a diversity of approaches to tackle those challenges.

In the Chicago Botanic Garden’s science program, we are conducting research on how human activities are affecting plants through climate change, habitat fragmentation, introduction of invasive species, pollinator loss, pollution, and more. These threats to plants are unlikely to diminish in the foreseeable future, and we are finding ways to conserve plants in changing and challenging environments. We are working hard to protect the plants and plant communities upon which we all depend. We are also working hard to create a pipeline into science for all—especially traditionally under-represented groups—through our Science Career Continuum, because diversity of plants and diversity of scientists are both good things.

Competition is heating up in the western United States. Invasive and native plants are racing to claim available land and resources. Alicia Foxx, who studies the interplay of roots of native and invasive plants, is glued to the action. The results of this contest, says the plant biology and conservation doctoral student at the Chicago Botanic Garden and Northwestern University, could be difficult to reverse.

Cheatgrass, which is an aggressive, invasive plant with a dense root system, is in the lead and spreading quickly across the west. Native plants are falling in its wake—especially when it comes to their delicate seedlings that lead to new generations.

Foxx is one of the scientists working to give native plants a leg (or root) up. She hypothesizes that a carefully assembled team of native plant seedlings with just the right root traits may be able to work together to outpace their competition.

“We often evaluate plants for the way they look above ground, but I think we have to look below ground as well,” she said. Foxx’s master thesis focused on a native grass known as squirreltail, and her hypothesis addressed the idea that the more robust the root system was in a native grass, the better it was at competing with cheatgrass. Now, “I’m looking more at how native plants behave in a community, as opposed to evaluating them one by one… How they interact with one another and how that might influence their performance or establishment in the Colorado plateau.”

In the desert climate, human-related disturbances such as mining, gas exploration, livestock trampling, or unnaturally frequent fires have killed off native plants and left barren patches of land behind that are susceptible to the arrival of cheatgrass.

Seedlings in the growth chamber

“Some of our activities are exacerbating the conditions [that are favorable for invasive plants]. We need to make sure that we have forage for the wildlife and the plants themselves, because they are important to us for different reasons, including the prevention of mudslides,” she said. “We are definitely confronted with a changing climate and it would be really difficult for us to reverse any damage we have caused, so we’re trying to shift the plant community so it can be here in 50 years.”

Garden conservation scientist Andrea Kramer, Ph.D. advises Foxx, and her mentorship has allowed Foxx to see how science theories created in a laboratory become real-life solutions in the field. “I think I’m very fortunate to work with Andrea, who works very closely with the Bureau of Land Management…it’s really nice to see that this gets replicated out in the world,” said Foxx. Seeds from their joint collecting trip in 2012 have been added to the Garden’s Dixon National Tallgrass Prairie Seed Bank.

In a way, Foxx is also learning from the invasive plants themselves. To develop her hypothesis, she considered the qualities of the invasive plants; those that succeeded had roots that are highly competitive for resources. After securing seeds from multiple sources, she is now working in the Garden’s greenhouse and the Population Biology Laboratory to grow native plants that may be up to the challenge. She is growing the seedlings in three different categories: a single plant, a group of the same species together, and a group of species that look different (such as a grass and a wildflower). In total, there will be 600 tubes holding plants. She will then evaluate their ability to establish themselves in a location and to survive over time.

On the right: a sunflower seedling (Helianthus annuus) next to a native grass (Pascopyrum smithii)

There has been very little research on plant roots, but Foxx said the traits of roots, such as how fibrous they are, their length, or the number of hair-like branches they form, tell us a lot about how they function.

“I’m hoping that looking at some of these root traits and looking at how these plants interact with one another will reveal something new or solidify some of the theories,” said Foxx.

She aims to have what she learns about the ecology of roots benefit restorations in the western United States. It is possible that her findings will shape thoughts in other regions as well, such as the prairies of the Midwest. Future research using the seeds Foxx collected could contribute to the National Seed Strategy for Rehabilitation and Restoration, of which the Garden is a key resource for research and seeds for future restoration needs.

The Chicago native has come a long way since she first discovered her love of botany during high school. After completing her research and her Ph.D., she hopes to nurture future scientists and citizen scientists through her ongoing work, and help them make the connections that can lead to a love of plants.

Last June, I headed up to Door County, Wisconsin, with Kay Havens, our director of plant science and conservation, for a 31-day trip to undertake our annual fieldwork. “A month at the beach!” you say, thinking it such a treat! Well, yes and no.

Four undergraduate students in our REU program joined us to track literal life and death events in two plant populations on the dunes of Lake Michigan. The dunes can be more than 20 degrees Fahrenheit hotter than ambient temperatures, and we work in the interdunal swales, where no lovely breezes off the lake can reach us. It is often well over 95 degrees in the dunes, even if it’s a balmy 75 degrees in Sturgeon Bay. But, no matter—we are on a mission! On days with the hot sun both beating down and reflecting up from the sand, we observed, measured, and recorded the births, deaths, and reproductive successes of one of our favorite plants: the threatened pitcher’s thistle (Cirsium pitcheri).

Pitcher’s thistle (Cirsium pitcheri)

We find every seedling we can, and place a flag next to it to help us keep track of the ones we’ve counted. We don’t want to miss a single one. Each seedling is a measure of successful reproduction for this monocarpic perennial. Monocarps—plants that only flower once before they die, are completely dependent upon producing as many successful offspring as they can, all in the quest to ensure that they just replace themselves. When all plants successfully replace themselves, a population is stable.

Just to replace yourself is a monumental undertaking for a plant that flowers once and then dies. Especially for pitcher’s thistle. The dunes are a harsh environment for a tiny baby plant. Many of them die—exposed to the heat, and without enough water to sustain them. We estimate that fewer than one in ten seeds germinate and survive each year, and in some years, only a small percent of those survive the winter to become a juvenile plant the next year. That means that each flowering plant must produce many seeds to replace itself. The good news? Generally, if a seedling survives to the juvenile stage, it has a much increased chance of survival to make it to the next stage—a vegetative plant—and the vast majority of those go on to reproduce at some point.

Kay Havens is ready to record data at Ship Canal Nature Preserve, owned by the Door County Land Trust.

However, seed germination and seedling survivorship and growth depend upon two things: where you come from and where you live. To look at this, we took 100 seeds from each of our two study populations and grew them in “seed baskets” in our study garden at the Chicago Botanic Garden. We also grew the same number in seed baskets at their respective home sites. Regardless of population, they germinated and grew very readily in our study garden. But there were very stark differences at our study sites in Door County: seed germination was 39% at one site, but only 9% at the other.

Pitcher’s thistle seedlings sprouted in one of our seed baskets at the Ship Canal Nature Preserve. The pair of yellow-green “leaves” opposite each other are actually cotyledons, or seed leaves, and are the first photosynthetic organs to emerge from the seed during germination.

These are pitcher’s thistle seedlings that have grown very large under the favorable conditions of the test garden on the south side of the Plant Science Center. In just one growing season, they have grown as large as plants three to four years old that grow under natural conditions.

Why the difference? Well, our first site is definitely more hospitable! Even we are happier to work here. It’s not nearly as hot, and the dune structure is more flat, so the breeze off the lake makes things more pleasant—for plants and people alike! And it appears to this observer’s eye that there’s more water available close to the surface here. This year, there are two large patches in the dune that have been perpetually damp. In contrast, our second population is literally high and dry, making life hard for the little pitcher’s thistle seedlings. How does this affect the prospects of these two populations overall? Stay tuned! We’ll let you know when we have finished our analysis of the long-term trends at these two very different sites.

One plant, two places—offering a fascinating glimpse of a life of contrasts.

The National Parks provide dream vacations for us nature lovers, but did you know they also serve as vital locations for forward-thinking conservation research by Chicago Botanic Garden scientists?

From sand to sea, the parks are a celebration of America’s diversity of plants, animals, and fungi, according to the Garden’s Chief Scientist Greg Mueller, Ph.D., who has worked in several parks throughout his career.

“National Parks were usually selected because they are areas of important biodiversity,” Dr. Mueller explained, “and they’ve been appropriately managed and looked after for up to 100 years. Often times they are the best place to do our work.”

As we celebrate this centennial year, he and his colleagues share recent and favorite work experiences with the parks.

Dr. Greg Mueller working at Big Thicket National Preserve, Texas, in 2007.

Take a glimpse into the wilderness from their eyes.

This summer, Mueller made a routine visit to Indiana Dunes National Lakeshore to examine the impact of pollution and other human-caused disturbances on the sensitive mushroom species and communities associated with trees. “One of the foci of our whole research program (at the Garden) is looking at that juxtaposition of humans and nature and how that can coexist. The Dunes National Lakeshore is just a great place to do that,” he explained, as it is unusually close to roads and industry.

Evelyn Williams, Ph.D., adjunct conservation scientist, relied on her fieldwork in Guadalupe Mountains National Park to study one of only two known populations of Lepidospartum burgessii, a rare gypsophile shrub, during a postdoctoral research appointment at the Garden. “We were able to work with park staff to study the species and make recommendations for management,” she said.

Dr. Evelyn Williams in Guadalupe Mountains National Park during 2014 field work. Photo by Adrienne Basey.

As a Conservation Land Management intern, Coleman Minney surveyed for the federally endangered Ptilimnium nodosum at the Chesapeake and Ohio Canal National Historical Park earlier this year. “The continued monitoring of this plant is important because its habitat is very susceptible to invasion from non-native plants,” explained Minney, who found the first natural population of the species on the main stem of the Potomac River in 20 years.

According to conservation scientist Andrea Kramer, Ph.D., “In many cases, National Parks provide the best and most intact examples of native plant communities in the country, and by studying them we can learn more about how to restore damaged or destroyed plant communities to support the people and wildlife that depend upon them.”

The parks have been a critical site for her work throughout her career. Initially, “I relied on the parks as sites for fieldwork on how wildflowers adapt to their local environment.”

Today, she is evaluating the results of restoration at sites in the Colorado Plateau by looking at data provided by collaborators. Her data covers areas that include Grand Canyon National Park, Capitol Reef National Park, and Canyon de Chelly National Monument.

Along with colleague Nora Talkington, a recent master’s degree graduate from the Garden’s program in plant biology and conservation who is now a botanist for the Navajo Nation, Dr. Kramer expects the results will inform future restoration work.

Dr. Kramer collects material from Arches National Park as a part of her dissertation research in 2003.

At Wrangell–St. Elias National Park and Preserve in Alaska, Natalie Balkam, a Conservation Land Management intern, has been hard at work collecting data on vegetation in the park and learning more about the intersection of people, science, and nature. “My time with the National Park Service has exposed me to the vastly interesting and complex mechanics of preserving and protecting a natural space,” she said. “And I get to work in one of the most beautiful places in the world—Alaska!”

The view from survey work in Elodea, part of the Wrangell–St. Elias National Park Preserve in Alaska. Photo courtesy National Park Service.

The benefits of conducting research with the National Parks extend beyond the ability to gather high-quality information, said Mueller. Parks retain records of research underway by others and facilitate collaborations between scientists. They may also provide previous research records to enhance a specific project. Their connections to research are tight. But nothing is as important as their ability to connect people with nature, said Mueller. “That need for experiencing nature, experiencing wilderness is something that’s critical for humankind.”